original development tree for Linux kernel GTP module; now long in mainline.
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/*
* TI EDMA DMA engine driver
*
* Copyright 2012 Texas Instruments
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation version 2.
*
* This program is distributed "as is" WITHOUT ANY WARRANTY of any
* kind, whether express or implied; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/platform_data/edma.h>
#include "dmaengine.h"
#include "virt-dma.h"
/*
* This will go away when the private EDMA API is folded
* into this driver and the platform device(s) are
* instantiated in the arch code. We can only get away
* with this simplification because DA8XX may not be built
* in the same kernel image with other DaVinci parts. This
* avoids having to sprinkle dmaengine driver platform devices
* and data throughout all the existing board files.
*/
#ifdef CONFIG_ARCH_DAVINCI_DA8XX
#define EDMA_CTLRS 2
#define EDMA_CHANS 32
#else
#define EDMA_CTLRS 1
#define EDMA_CHANS 64
#endif /* CONFIG_ARCH_DAVINCI_DA8XX */
/* Max of 16 segments per channel to conserve PaRAM slots */
#define MAX_NR_SG 16
#define EDMA_MAX_SLOTS MAX_NR_SG
#define EDMA_DESCRIPTORS 16
struct edma_desc {
struct virt_dma_desc vdesc;
struct list_head node;
int absync;
int pset_nr;
int processed;
struct edmacc_param pset[0];
};
struct edma_cc;
struct edma_chan {
struct virt_dma_chan vchan;
struct list_head node;
struct edma_desc *edesc;
struct edma_cc *ecc;
int ch_num;
bool alloced;
int slot[EDMA_MAX_SLOTS];
int missed;
struct dma_slave_config cfg;
};
struct edma_cc {
int ctlr;
struct dma_device dma_slave;
struct edma_chan slave_chans[EDMA_CHANS];
int num_slave_chans;
int dummy_slot;
};
static inline struct edma_cc *to_edma_cc(struct dma_device *d)
{
return container_of(d, struct edma_cc, dma_slave);
}
static inline struct edma_chan *to_edma_chan(struct dma_chan *c)
{
return container_of(c, struct edma_chan, vchan.chan);
}
static inline struct edma_desc
*to_edma_desc(struct dma_async_tx_descriptor *tx)
{
return container_of(tx, struct edma_desc, vdesc.tx);
}
static void edma_desc_free(struct virt_dma_desc *vdesc)
{
kfree(container_of(vdesc, struct edma_desc, vdesc));
}
/* Dispatch a queued descriptor to the controller (caller holds lock) */
static void edma_execute(struct edma_chan *echan)
{
struct virt_dma_desc *vdesc;
struct edma_desc *edesc;
struct device *dev = echan->vchan.chan.device->dev;
int i, j, left, nslots;
/* If either we processed all psets or we're still not started */
if (!echan->edesc ||
echan->edesc->pset_nr == echan->edesc->processed) {
/* Get next vdesc */
vdesc = vchan_next_desc(&echan->vchan);
if (!vdesc) {
echan->edesc = NULL;
return;
}
list_del(&vdesc->node);
echan->edesc = to_edma_desc(&vdesc->tx);
}
edesc = echan->edesc;
/* Find out how many left */
left = edesc->pset_nr - edesc->processed;
nslots = min(MAX_NR_SG, left);
/* Write descriptor PaRAM set(s) */
for (i = 0; i < nslots; i++) {
j = i + edesc->processed;
edma_write_slot(echan->slot[i], &edesc->pset[j]);
dev_dbg(echan->vchan.chan.device->dev,
"\n pset[%d]:\n"
" chnum\t%d\n"
" slot\t%d\n"
" opt\t%08x\n"
" src\t%08x\n"
" dst\t%08x\n"
" abcnt\t%08x\n"
" ccnt\t%08x\n"
" bidx\t%08x\n"
" cidx\t%08x\n"
" lkrld\t%08x\n",
j, echan->ch_num, echan->slot[i],
edesc->pset[j].opt,
edesc->pset[j].src,
edesc->pset[j].dst,
edesc->pset[j].a_b_cnt,
edesc->pset[j].ccnt,
edesc->pset[j].src_dst_bidx,
edesc->pset[j].src_dst_cidx,
edesc->pset[j].link_bcntrld);
/* Link to the previous slot if not the last set */
if (i != (nslots - 1))
edma_link(echan->slot[i], echan->slot[i+1]);
}
edesc->processed += nslots;
/*
* If this is either the last set in a set of SG-list transactions
* then setup a link to the dummy slot, this results in all future
* events being absorbed and that's OK because we're done
*/
if (edesc->processed == edesc->pset_nr)
edma_link(echan->slot[nslots-1], echan->ecc->dummy_slot);
edma_resume(echan->ch_num);
if (edesc->processed <= MAX_NR_SG) {
dev_dbg(dev, "first transfer starting %d\n", echan->ch_num);
edma_start(echan->ch_num);
}
/*
* This happens due to setup times between intermediate transfers
* in long SG lists which have to be broken up into transfers of
* MAX_NR_SG
*/
if (echan->missed) {
dev_dbg(dev, "missed event in execute detected\n");
edma_clean_channel(echan->ch_num);
edma_stop(echan->ch_num);
edma_start(echan->ch_num);
edma_trigger_channel(echan->ch_num);
echan->missed = 0;
}
}
static int edma_terminate_all(struct edma_chan *echan)
{
unsigned long flags;
LIST_HEAD(head);
spin_lock_irqsave(&echan->vchan.lock, flags);
/*
* Stop DMA activity: we assume the callback will not be called
* after edma_dma() returns (even if it does, it will see
* echan->edesc is NULL and exit.)
*/
if (echan->edesc) {
echan->edesc = NULL;
edma_stop(echan->ch_num);
}
vchan_get_all_descriptors(&echan->vchan, &head);
spin_unlock_irqrestore(&echan->vchan.lock, flags);
vchan_dma_desc_free_list(&echan->vchan, &head);
return 0;
}
static int edma_slave_config(struct edma_chan *echan,
struct dma_slave_config *cfg)
{
if (cfg->src_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES ||
cfg->dst_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES)
return -EINVAL;
memcpy(&echan->cfg, cfg, sizeof(echan->cfg));
return 0;
}
static int edma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
unsigned long arg)
{
int ret = 0;
struct dma_slave_config *config;
struct edma_chan *echan = to_edma_chan(chan);
switch (cmd) {
case DMA_TERMINATE_ALL:
edma_terminate_all(echan);
break;
case DMA_SLAVE_CONFIG:
config = (struct dma_slave_config *)arg;
ret = edma_slave_config(echan, config);
break;
default:
ret = -ENOSYS;
}
return ret;
}
static struct dma_async_tx_descriptor *edma_prep_slave_sg(
struct dma_chan *chan, struct scatterlist *sgl,
unsigned int sg_len, enum dma_transfer_direction direction,
unsigned long tx_flags, void *context)
{
struct edma_chan *echan = to_edma_chan(chan);
struct device *dev = chan->device->dev;
struct edma_desc *edesc;
dma_addr_t dev_addr;
enum dma_slave_buswidth dev_width;
u32 burst;
struct scatterlist *sg;
int acnt, bcnt, ccnt, src, dst, cidx;
int src_bidx, dst_bidx, src_cidx, dst_cidx;
int i, nslots;
if (unlikely(!echan || !sgl || !sg_len))
return NULL;
if (direction == DMA_DEV_TO_MEM) {
dev_addr = echan->cfg.src_addr;
dev_width = echan->cfg.src_addr_width;
burst = echan->cfg.src_maxburst;
} else if (direction == DMA_MEM_TO_DEV) {
dev_addr = echan->cfg.dst_addr;
dev_width = echan->cfg.dst_addr_width;
burst = echan->cfg.dst_maxburst;
} else {
dev_err(dev, "%s: bad direction?\n", __func__);
return NULL;
}
if (dev_width == DMA_SLAVE_BUSWIDTH_UNDEFINED) {
dev_err(dev, "Undefined slave buswidth\n");
return NULL;
}
edesc = kzalloc(sizeof(*edesc) + sg_len *
sizeof(edesc->pset[0]), GFP_ATOMIC);
if (!edesc) {
dev_dbg(dev, "Failed to allocate a descriptor\n");
return NULL;
}
edesc->pset_nr = sg_len;
/* Allocate a PaRAM slot, if needed */
nslots = min_t(unsigned, MAX_NR_SG, sg_len);
for (i = 0; i < nslots; i++) {
if (echan->slot[i] < 0) {
echan->slot[i] =
edma_alloc_slot(EDMA_CTLR(echan->ch_num),
EDMA_SLOT_ANY);
if (echan->slot[i] < 0) {
dev_err(dev, "Failed to allocate slot\n");
return NULL;
}
}
}
/* Configure PaRAM sets for each SG */
for_each_sg(sgl, sg, sg_len, i) {
acnt = dev_width;
/*
* If the maxburst is equal to the fifo width, use
* A-synced transfers. This allows for large contiguous
* buffer transfers using only one PaRAM set.
*/
if (burst == 1) {
edesc->absync = false;
ccnt = sg_dma_len(sg) / acnt / (SZ_64K - 1);
bcnt = sg_dma_len(sg) / acnt - ccnt * (SZ_64K - 1);
if (bcnt)
ccnt++;
else
bcnt = SZ_64K - 1;
cidx = acnt;
/*
* If maxburst is greater than the fifo address_width,
* use AB-synced transfers where A count is the fifo
* address_width and B count is the maxburst. In this
* case, we are limited to transfers of C count frames
* of (address_width * maxburst) where C count is limited
* to SZ_64K-1. This places an upper bound on the length
* of an SG segment that can be handled.
*/
} else {
edesc->absync = true;
bcnt = burst;
ccnt = sg_dma_len(sg) / (acnt * bcnt);
if (ccnt > (SZ_64K - 1)) {
dev_err(dev, "Exceeded max SG segment size\n");
return NULL;
}
cidx = acnt * bcnt;
}
if (direction == DMA_MEM_TO_DEV) {
src = sg_dma_address(sg);
dst = dev_addr;
src_bidx = acnt;
src_cidx = cidx;
dst_bidx = 0;
dst_cidx = 0;
} else {
src = dev_addr;
dst = sg_dma_address(sg);
src_bidx = 0;
src_cidx = 0;
dst_bidx = acnt;
dst_cidx = cidx;
}
edesc->pset[i].opt = EDMA_TCC(EDMA_CHAN_SLOT(echan->ch_num));
/* Configure A or AB synchronized transfers */
if (edesc->absync)
edesc->pset[i].opt |= SYNCDIM;
/* If this is the last in a current SG set of transactions,
enable interrupts so that next set is processed */
if (!((i+1) % MAX_NR_SG))
edesc->pset[i].opt |= TCINTEN;
/* If this is the last set, enable completion interrupt flag */
if (i == sg_len - 1)
edesc->pset[i].opt |= TCINTEN;
edesc->pset[i].src = src;
edesc->pset[i].dst = dst;
edesc->pset[i].src_dst_bidx = (dst_bidx << 16) | src_bidx;
edesc->pset[i].src_dst_cidx = (dst_cidx << 16) | src_cidx;
edesc->pset[i].a_b_cnt = bcnt << 16 | acnt;
edesc->pset[i].ccnt = ccnt;
edesc->pset[i].link_bcntrld = 0xffffffff;
}
return vchan_tx_prep(&echan->vchan, &edesc->vdesc, tx_flags);
}
static void edma_callback(unsigned ch_num, u16 ch_status, void *data)
{
struct edma_chan *echan = data;
struct device *dev = echan->vchan.chan.device->dev;
struct edma_desc *edesc;
unsigned long flags;
struct edmacc_param p;
/* Pause the channel */
edma_pause(echan->ch_num);
switch (ch_status) {
case DMA_COMPLETE:
spin_lock_irqsave(&echan->vchan.lock, flags);
edesc = echan->edesc;
if (edesc) {
if (edesc->processed == edesc->pset_nr) {
dev_dbg(dev, "Transfer complete, stopping channel %d\n", ch_num);
edma_stop(echan->ch_num);
vchan_cookie_complete(&edesc->vdesc);
} else {
dev_dbg(dev, "Intermediate transfer complete on channel %d\n", ch_num);
}
edma_execute(echan);
}
spin_unlock_irqrestore(&echan->vchan.lock, flags);
break;
case DMA_CC_ERROR:
spin_lock_irqsave(&echan->vchan.lock, flags);
edma_read_slot(EDMA_CHAN_SLOT(echan->slot[0]), &p);
/*
* Issue later based on missed flag which will be sure
* to happen as:
* (1) we finished transmitting an intermediate slot and
* edma_execute is coming up.
* (2) or we finished current transfer and issue will
* call edma_execute.
*
* Important note: issuing can be dangerous here and
* lead to some nasty recursion when we are in a NULL
* slot. So we avoid doing so and set the missed flag.
*/
if (p.a_b_cnt == 0 && p.ccnt == 0) {
dev_dbg(dev, "Error occurred, looks like slot is null, just setting miss\n");
echan->missed = 1;
} else {
/*
* The slot is already programmed but the event got
* missed, so its safe to issue it here.
*/
dev_dbg(dev, "Error occurred but slot is non-null, TRIGGERING\n");
edma_clean_channel(echan->ch_num);
edma_stop(echan->ch_num);
edma_start(echan->ch_num);
edma_trigger_channel(echan->ch_num);
}
spin_unlock_irqrestore(&echan->vchan.lock, flags);
break;
default:
break;
}
}
/* Alloc channel resources */
static int edma_alloc_chan_resources(struct dma_chan *chan)
{
struct edma_chan *echan = to_edma_chan(chan);
struct device *dev = chan->device->dev;
int ret;
int a_ch_num;
LIST_HEAD(descs);
a_ch_num = edma_alloc_channel(echan->ch_num, edma_callback,
chan, EVENTQ_DEFAULT);
if (a_ch_num < 0) {
ret = -ENODEV;
goto err_no_chan;
}
if (a_ch_num != echan->ch_num) {
dev_err(dev, "failed to allocate requested channel %u:%u\n",
EDMA_CTLR(echan->ch_num),
EDMA_CHAN_SLOT(echan->ch_num));
ret = -ENODEV;
goto err_wrong_chan;
}
echan->alloced = true;
echan->slot[0] = echan->ch_num;
dev_info(dev, "allocated channel for %u:%u\n",
EDMA_CTLR(echan->ch_num), EDMA_CHAN_SLOT(echan->ch_num));
return 0;
err_wrong_chan:
edma_free_channel(a_ch_num);
err_no_chan:
return ret;
}
/* Free channel resources */
static void edma_free_chan_resources(struct dma_chan *chan)
{
struct edma_chan *echan = to_edma_chan(chan);
struct device *dev = chan->device->dev;
int i;
/* Terminate transfers */
edma_stop(echan->ch_num);
vchan_free_chan_resources(&echan->vchan);
/* Free EDMA PaRAM slots */
for (i = 1; i < EDMA_MAX_SLOTS; i++) {
if (echan->slot[i] >= 0) {
edma_free_slot(echan->slot[i]);
echan->slot[i] = -1;
}
}
/* Free EDMA channel */
if (echan->alloced) {
edma_free_channel(echan->ch_num);
echan->alloced = false;
}
dev_info(dev, "freeing channel for %u\n", echan->ch_num);
}
/* Send pending descriptor to hardware */
static void edma_issue_pending(struct dma_chan *chan)
{
struct edma_chan *echan = to_edma_chan(chan);
unsigned long flags;
spin_lock_irqsave(&echan->vchan.lock, flags);
if (vchan_issue_pending(&echan->vchan) && !echan->edesc)
edma_execute(echan);
spin_unlock_irqrestore(&echan->vchan.lock, flags);
}
static size_t edma_desc_size(struct edma_desc *edesc)
{
int i;
size_t size;
if (edesc->absync)
for (size = i = 0; i < edesc->pset_nr; i++)
size += (edesc->pset[i].a_b_cnt & 0xffff) *
(edesc->pset[i].a_b_cnt >> 16) *
edesc->pset[i].ccnt;
else
size = (edesc->pset[0].a_b_cnt & 0xffff) *
(edesc->pset[0].a_b_cnt >> 16) +
(edesc->pset[0].a_b_cnt & 0xffff) *
(SZ_64K - 1) * edesc->pset[0].ccnt;
return size;
}
/* Check request completion status */
static enum dma_status edma_tx_status(struct dma_chan *chan,
dma_cookie_t cookie,
struct dma_tx_state *txstate)
{
struct edma_chan *echan = to_edma_chan(chan);
struct virt_dma_desc *vdesc;
enum dma_status ret;
unsigned long flags;
ret = dma_cookie_status(chan, cookie, txstate);
if (ret == DMA_SUCCESS || !txstate)
return ret;
spin_lock_irqsave(&echan->vchan.lock, flags);
vdesc = vchan_find_desc(&echan->vchan, cookie);
if (vdesc) {
txstate->residue = edma_desc_size(to_edma_desc(&vdesc->tx));
} else if (echan->edesc && echan->edesc->vdesc.tx.cookie == cookie) {
struct edma_desc *edesc = echan->edesc;
txstate->residue = edma_desc_size(edesc);
}
spin_unlock_irqrestore(&echan->vchan.lock, flags);
return ret;
}
static void __init edma_chan_init(struct edma_cc *ecc,
struct dma_device *dma,
struct edma_chan *echans)
{
int i, j;
for (i = 0; i < EDMA_CHANS; i++) {
struct edma_chan *echan = &echans[i];
echan->ch_num = EDMA_CTLR_CHAN(ecc->ctlr, i);
echan->ecc = ecc;
echan->vchan.desc_free = edma_desc_free;
vchan_init(&echan->vchan, dma);
INIT_LIST_HEAD(&echan->node);
for (j = 0; j < EDMA_MAX_SLOTS; j++)
echan->slot[j] = -1;
}
}
static void edma_dma_init(struct edma_cc *ecc, struct dma_device *dma,
struct device *dev)
{
dma->device_prep_slave_sg = edma_prep_slave_sg;
dma->device_alloc_chan_resources = edma_alloc_chan_resources;
dma->device_free_chan_resources = edma_free_chan_resources;
dma->device_issue_pending = edma_issue_pending;
dma->device_tx_status = edma_tx_status;
dma->device_control = edma_control;
dma->dev = dev;
INIT_LIST_HEAD(&dma->channels);
}
static int edma_probe(struct platform_device *pdev)
{
struct edma_cc *ecc;
int ret;
ecc = devm_kzalloc(&pdev->dev, sizeof(*ecc), GFP_KERNEL);
if (!ecc) {
dev_err(&pdev->dev, "Can't allocate controller\n");
return -ENOMEM;
}
ecc->ctlr = pdev->id;
ecc->dummy_slot = edma_alloc_slot(ecc->ctlr, EDMA_SLOT_ANY);
if (ecc->dummy_slot < 0) {
dev_err(&pdev->dev, "Can't allocate PaRAM dummy slot\n");
return -EIO;
}
dma_cap_zero(ecc->dma_slave.cap_mask);
dma_cap_set(DMA_SLAVE, ecc->dma_slave.cap_mask);
edma_dma_init(ecc, &ecc->dma_slave, &pdev->dev);
edma_chan_init(ecc, &ecc->dma_slave, ecc->slave_chans);
ret = dma_async_device_register(&ecc->dma_slave);
if (ret)
goto err_reg1;
platform_set_drvdata(pdev, ecc);
dev_info(&pdev->dev, "TI EDMA DMA engine driver\n");
return 0;
err_reg1:
edma_free_slot(ecc->dummy_slot);
return ret;
}
static int edma_remove(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct edma_cc *ecc = dev_get_drvdata(dev);
dma_async_device_unregister(&ecc->dma_slave);
edma_free_slot(ecc->dummy_slot);
return 0;
}
static struct platform_driver edma_driver = {
.probe = edma_probe,
.remove = edma_remove,
.driver = {
.name = "edma-dma-engine",
.owner = THIS_MODULE,
},
};
bool edma_filter_fn(struct dma_chan *chan, void *param)
{
if (chan->device->dev->driver == &edma_driver.driver) {
struct edma_chan *echan = to_edma_chan(chan);
unsigned ch_req = *(unsigned *)param;
return ch_req == echan->ch_num;
}
return false;
}
EXPORT_SYMBOL(edma_filter_fn);
static struct platform_device *pdev0, *pdev1;
static const struct platform_device_info edma_dev_info0 = {
.name = "edma-dma-engine",
.id = 0,
};
static const struct platform_device_info edma_dev_info1 = {
.name = "edma-dma-engine",
.id = 1,
};
static int edma_init(void)
{
int ret = platform_driver_register(&edma_driver);
if (ret == 0) {
pdev0 = platform_device_register_full(&edma_dev_info0);
if (IS_ERR(pdev0)) {
platform_driver_unregister(&edma_driver);
ret = PTR_ERR(pdev0);
goto out;
}
pdev0->dev.dma_mask = &pdev0->dev.coherent_dma_mask;
pdev0->dev.coherent_dma_mask = DMA_BIT_MASK(32);
}
if (EDMA_CTLRS == 2) {
pdev1 = platform_device_register_full(&edma_dev_info1);
if (IS_ERR(pdev1)) {
platform_driver_unregister(&edma_driver);
platform_device_unregister(pdev0);
ret = PTR_ERR(pdev1);
}
pdev1->dev.dma_mask = &pdev1->dev.coherent_dma_mask;
pdev1->dev.coherent_dma_mask = DMA_BIT_MASK(32);
}
out:
return ret;
}
subsys_initcall(edma_init);
static void __exit edma_exit(void)
{
platform_device_unregister(pdev0);
if (pdev1)
platform_device_unregister(pdev1);
platform_driver_unregister(&edma_driver);
}
module_exit(edma_exit);
MODULE_AUTHOR("Matt Porter <matt.porter@linaro.org>");
MODULE_DESCRIPTION("TI EDMA DMA engine driver");
MODULE_LICENSE("GPL v2");